Effect of Resin Composition on the Remineralizing Ability of Amorphous Calcium Phosphate-Based Polymeric Composites

Published

May 15, 2000

Author(s)

Drago Skrtic, Joseph M. Antonucci, E D. Eanes

Abstract

Five photoactivated resins, designated BTHZ, TP, U0H, U66H and U132H, were evaluated for the effects of the chemical structure and compositional variations of the resins on the release of mineral (Ca2+ and PO4) ions from ACPfilled composites, i.e. their remineralizition potential. Composite pastes were made up of mass fraction of 40 % of either unhybridized, P2O7stabilized ACP (PyroACP), silica- or zirconiahybridized ACP (TEOSACP and ZrACP, respectively) with mass fraction of 60 % of each resin. The remineralizing ability of the composites was tested by immersing individual disk specimens in buffered saline solutions (pH=7.40, ionic strength = 0.13 mol/L, 37oC, continuous magnetic stirring) for at least 300 hours (3 independent runs in each experimental group). Aliquots were taken at the predetermined time intervals, filtered, and the filtrates analyzed for their Ca2+ and PO4 contents using atomic spectroscopy and UV/VIS spectrophotometry, respectively. The thermodynamic stability of immersion solutions was calculated as their supersaturation relative to stoichiometric HAP and expressed as the Gibbs free energy, DGo. Elevated Ca2+ and PO4 ion concentrations were sustained in all BTHZ and UH resins. However, over time TP composites failed to maintain a favorable remineralization potential due to the resin retention of released Ca2+ via ion binding by carboxylic acid groups of PMGDMA. Remineralizing ability of PyroACP composites ranked (BTHZ, U132H) >TP> (U0H, U66H). Composites based on the TEOS- or ZrACP, and U0H, U66H or U132H had significantly higher (p , 0.0013) remineralization potential compared to the similarly prepared PyroACP UH composites. Hybridization of the fillers had no effect on the ion release from BTHZ composites. However, internal conversion of ACP to HAP was significantly reduced or almost completely inhibited in the case of BTHZ and UH/ hybridized ACP composites.Supported by NIST and a grant from the ADAHF.Five photoactivated resins, designated BTHZ, TP, U0H, U66H and U132H, were evaluated for the effects of the chemical structure and compositional variations of the resins on the release of mineral (Ca2+ and PO4) ions from ACPfilled composites, i.e. their remineralizition potential. Composite pastes were made up of mass fraction of 40 % of either unhybridized, P2O7stabilized ACP (PyroACP), silica- or zirconiahybridized ACP (TEOSACP and ZrACP, respectively) with mass fraction of 60 % of each resin. The remineralizing ability of the composites was tested by immersing individual disk specimens in buffered saline solutions (pH=7.40, ionic strength = 0.13 mol/L, 37oC, continuous magnetic stirring) for at least 300 hours (3 independent runs in each experimental group). Aliquots were taken at the predetermined time intervals, filtered, and the filtrates analyzed for their Ca2+ and PO4 contents using atomic spectroscopy and UV/VIS spectrophotometry, respectively. The thermodynamic stability of immersion solutions was calculated as their supersaturation relative to stoichiometric HAP and expressed as the Gibbs free energy, DGo. Elevated Ca2+ and PO4 ion concentrations were sustained in all BTHZ and UH resins. However, over time TP composites failed to maintain a favorable remineralization potential due to the resin retention of released Ca2+ via ion binding by carboxylic acid groups of PMGDMA. Remineralizing ability of PyroACP composites ranked (BTHZ, U132H) >TP> (U0H, U66H). Composites based on the TEOS- or ZrACP, and U0H, U66H or U132H had significantly higher (p , 0.0013) remineralization potential compared to the similarly prepared PyroACP UH composites. Hybridization of the fillers had no effect on the ion release from BTHZ composites. However, internal conversion of ACP to HAP was significantly reduced or almost completely inhibited in the case of BTHZ and UH/ hybridized ACP composites.Supported by NIST and a grant from the ADAHF.

Proceedings Title

The 6th World Biomaterials Congress

Conference Dates

May 15-20, 2000

Conference Title

World Biomaterials Congress

Pub Type

Conferences

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Keywords

amorphous, calcium phosphate, composite, hybridized, ion release, remineralization, resin

Citation

Skrtic, D. , Antonucci, J. and Eanes, E. (2000), Effect of Resin Composition on the Remineralizing Ability of Amorphous Calcium Phosphate-Based Polymeric Composites, The 6th World Biomaterials Congress, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851618 (Accessed May 17, 2024)